Catheter ablation for atrial fibrillation (AF) is a procedure that is an effective treatment for common arrhythmia. Arrhythmia, also called dysrhythmia, is an irregular or abnormal heart rhythm. The procedure uses a catheter which gathers data to pinpoint the location of faulty tissue in the heart (e.g. electrical mapping). The catheter is then used to ablate and destroy the faulty tissue. A variety of serious complications have been reported with catheter ablation for AF, including pulmonary vein stenosis, cardiac perforation, thromboembolism, vascular complications, and phrenic nerve injury. Atrioesophageal fistula, thought to result from thermal injury of the esophagus due to its close position to the posterior left atrial (LA) wall, is a rare but often fatal complication of catheter ablation for AF.
Prior methods for detecting and avoiding esophageal injury during left atrial catheter ablation include fluoroscopic contrast visualization to monitor placement of the ablation catheter. Temperature monitoring of the esophagus has also been used. These methods are combined with limiting the amount of energy applied to areas of the heart where collateral damage is likely (e.g. near the esophagus). However, limiting energy delivery near the esophagus may not provide proper therapy, and thus the arrhythmia may not be successfully treated.